Visibility of Luna and Lunar Crescent

'fte najor achjevem€nt of this m* is th. romulation of t neq sincle pstuerer
cireion on lhe b6is of rhe Fchniqus deleloped bv Bruin and Yallop using lhe
bngnrrc$ modcls develoFd bv Sch&fer dd othe6 rhc visibilirv cuFes and thc
liniting visibilily cwes aE developed for crceenls ol diffeEnl widrhs ll'!l wcrc
actually obened tnd hav. bcen rcpodcd in lile6tue Bruin dcvelopcd lhe$ cllvcs on
|he bdis or{i) lhe ale6se bdshlnss ofthc tult M@n md thc wv i dalt,s *nh rhe
decr€sing alftude abole hoi@h and (ii) tbe avedge brighiness ot the skv dudrg
t*ilid &d fic way n depends on lhc dolld d'prc$ion b'lov horizo' On lhc olher
hand tc bave usd rhe adual brightncss for Ihe obscb-ed cEsc€nB ola fixed wid r llEn
lor tn sne ofobselvation we hare calculared th' al ude of skv poins bavins rtrc sms
bridft$ d $ar ol lh€ dcsenr for difrercht solar depcsions such compuratios m
Ep€ai.d for a nunber ofobseryed cE$e 5 of the sahe wjd$ al dilIelenl localions and
dmes. The aliudes or thc skv poitrts lhu obt'ined re ten 'vc6Bcd
our Thc wnole
prccess h rhe. rcpeaFd for cnsce.t ofdilTereni widlhs
These conpulations tesulled inlo our lisibililv curycs ed $c linnins visibihv
curyes. The linitihB lisibilitv cses we have obEined ae slishtlt diferenl
'iod
$ose
of Bruii with nini@ slightlv displ&cd The ntlighl linc joining thc ninina oi dEs
cudes has a slope of9 3/5 as compaftd to 9/5 for Bruin s cutves Tnis lcads lo slighd,
differe b.sl dme of visibililv" which is 4 l/9 1 rine th€ noo'elsuosl lag aller thc
suet (6 cohPdcd lo Yallop s be$ tine which 4/g rincs $e noonst-sunscl lae afiet
rhe suset). Th€ bdic dala ob$inod fion the ninim olor liniringlisibilnv cu8e l-rttd
b a fiird desee Polvnodial tsuls inlo the fouowine visibihv pdamslcr:
s =(.4RCV - (4351 31 /3 + 2222075057t4! - 5 422641ritf + l04l4l?tt)/l0
we have als dedeed visibilitt condi$ons in a tum€t simild io lbar of Yallop'
Our vhibihy condilions tre sliCh v difiere lron those of Yallop Howevet' ltplj_'n8
our model on the obseNatioml dal! the succcss pcrcenrage is iound lo b' thc besl
dongn all the dot nodels tll erist and lhar dc €ncd dd conpaed in lhis \orr'
Thc e6on is tbat our model is baed on $e acrual skv brighhre$ and lhe btislrhss oi
201